EXAMPLE 22 Constructing cumulative frequency and cumulative relative frequency distributions

Table 35 contains the total 2013 attendance for 25 Major League Baseball teams.

Table 2.83: TABLE 35 Total 2013 attendance for 25 Major League Baseball teams (in millions)
1.5 1.6 1.6 1.7 1.8
1.8 1.8 1.8 2.1 2.1
2.3 2.4 2.5 2.5 2.5
2.6 2.6 2.8 2.8 3.0
3.0 3.1 3.2 3.3 3.7
Table 2.83: Source: http://mlb.mlb.com.

The first three columns in Table 36 below contain the frequency distribution and relative frequency distribution for the attendance data. Construct a cumulative frequency distribution and a cumulative relative frequency distribution for the attendance figures.

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Solution

To find the cumulative frequency for a class, add the frequencies of the classes equal to or below the upper class limit of that class. For example, the cumulative frequency for the class is the sum of the frequency for this class and for the class . The procedure for the cumulative relative frequencies is similar. The results are shown in the last two columns of Table 36, where we can see that more than three-quarters (0.76) of these teams had attendance of less than 3 million.

Table 2.84: TABLE 36 Cumulative frequency distribution and cumulative relative frequency distribution
Attendance Frequency Relative
frequency		 Cumulative
frequency		 Cumulative
relative frequency
8 0.32 8 0.32
4 0.16
7 0.28
5 0.20
1 0.04
Total 25 1.00

NOW YOU CAN DO

Exercises 9–12.